DALLAS (AP) – Federal regulators want to fine AirTran Airways $250,000 for failing to properly repair or test a key sensor on a plane that was struck by lightning.

Regulators say AirTran operated the Boeing 737 on four flights in March 2009 before doing proper repairs.

The Federal Aviation Administration said Thursday that AirTran maintenance crews removed then reinstalled a damaged sensor without performing a required test or repairing the part immediately. The part, called an angle-of-attack sensor, is designed to warn of potential loss of lift that could lead to a stall.

The FAA said AirTran wrongly determined that it could put off repairing the sensor. The FAA said the sensor is among the systems that must be working to fly a plane legally.

AirTran spokesman Christopher White said the airline was trying to resolve the matter with the FAA.

“At no time was safety compromised during these flights,” he said.

Airlines have 30 days to appeal after the FAA issues a proposed civil penalty. Negotiations can drag on for months and result in a lesser fine or none at all.

AirTran was an independent airline at the time of the incident but is now owned by Southwest Airlines Co.